I'm powerless if you won't use it.

I can't forbid Bob coming here; you can." Helen hesitated.

It was unfortunate that both were in an abnormal mood.
They had borne some strain, and the shock of the disaster to the crop had left them with jangled nerves.

This clouded Helen's judgment, but reenforced her pride.

She had meant well when she tried to help Sadie with Bob, and could not give way to her husband's unreasonable prejudice.